.308 subsonic in an AR platform?

[Wheedle]

I did search the forums, but could not find quite the answer to my question.
I was contemplating a .300Blackout build for shooting suppressed and subsonic, but I already have two LR308 platform rifles, a handful of spare parts, and a pile of mags... and I like commonality. Anyway, I know it is possible to load .308Win to subsonic, but how problematic would it be to get it to function reliably and reasonably accurately in the LR308 platform? Has anyone around the Hide tried, and what were the results?

 

[EXTREMEPREJUDICE]

http://www.davidtubb.com/precisionammo-308-2Holeammo

 

[Snuby642]

Accurate heavy subs like a fast twist in 300 blk, 16 inch barrels.
Don't think 308 will be any different at 1050 fps.
Have seen some posts of 308 using 1/10 subs but the mfgs advise otherwise.
Shoot whatever you want without the can to see if it stabilizes first.

 

[jda2631]

Or you could buy a .300BLK rifle or kit for under $500.

^^This^^ It's going to be pretty difficult, and probably pretty expensive, to get 308 subs cycling reliably. Not to mention the gun will be bigger and heavier and ammo more expensive.

 

[putput30]

It might not be a bad idea to wait and see what ever becomes of the 8.6 creedmoor that should be released at Shot. 300+ grain subs and 150 grainers at 2500 out of a 12.5 inch barrel sounds appealing.

 

[jda2631]

It might not be a bad idea to wait and see what ever becomes of the 8.6 creedmoor that should be released at Shot. 300+ grain subs and 150 grainers at 2500 out of a 12.5 inch barrel sounds appealing.

I agree, I'm very intrigued by it. Only downside is you need a 338 can.

 

[Yondering]

Yeah, I have an RPR in .308 and if my straight-pull 6.5G comes together the way I want, I've considered rebarreling the RPR to 8.6 as a big brother to my .300BO Savage. That or fuck around with necking up a .308 case.

That's called a 338 Federal, been around for a while already. Or go to a 358 Win, which has been around for a whole lot longer.

Pretty much every caliber up to 45 has been done on the 308 case already, and most of the practical versions are factory cartridges.

 

[Wheedle]

Thanks everyone... looks like a .300BO build is in my future.

 

[Greg Langelius *]

Or... This.

The x39 might work in this with subsonic heavies...

I get kinda unenthusiastic about just-outta-Wildcats when the near-ideal SS cartridge already exists. The BO s not so straightforward a slam dunk as lots of us would like to believe.

My shooting Buddy went through a lot of back-flips to get his BO AR running right.

Greg

 

[jda2631]

Or... This.

The x39 might work in this with subsonic heavies...

I get kinda unenthusiastic about just-outta-Wildcats when the near-ideal SS cartridge already exists. The BO s not so straightforward a slam dunk as lots of us would like to believe.

My shooting Buddy went through a lot of back-flips to get his BO AR running right.

Greg

I've built 3 blk's, a 7", 8.5" and 10.5". the 7" was a cheap, complete kit from palmetto. They have all run great. Only time I ran into any issue was when I put a can on that 7" from palmetto with their fixed GB. Put an adjustable GB on it and tuned it, no issue since. 300 BLK is the easy button for shooting supers and subs without fiddling with gas between the 2. If the plan is to shoot subs, then there is no reason to get anything other than a 300blk IMO. Just works too well and it's too easy.

 

[oldfatguy]

308 subs are kind of like 5.556 subs. Might as well shoot 22LR instead of trying to get 5.56 subs to run in an AR.

OFG

 

[Raffica762]

I got 245gr noe cast 308 to stabilize and run sub sonic in a 308 gas gun

 

[Wheedle]

I got 245gr noe cast 308 to stabilize and run sub sonic in a 308 gas gun

How much tinkering and tuning did that take? Did it end up being finicky?

 

[Raffica762]

Not really 220gr bullets work too it's really all in the gas system...mine is a carbine gas setup but this load wont work in my rifle gas assy

 

[Raffica762]

How much tinkering and tuning did that take? Did it end up being finicky?

Try 23g 4350 imr and seat em deep